Acute Assessment of Traumatic Brain Injury and Post-Traumatic Stress After Exposure to a Deployment-Related Explosive Blast.

Introduction: Traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) are two of the signature injuries in military service members who have been exposed to explosive blasts during deployments to Iraq and Afghanistan. Acute stress disorder (ASD), which occurs within 2-30 d after trauma exposure, is a more immediate psychological reaction predictive of the later development of PTSD. Most previous studies have evaluated service members after their return from deployment, which is often months or years after the initial blast exposure. The current study is the first large study to collect psychological and neuropsychological data from active duty service members within a few days after blast exposure. Materials and Methods: Recruitment for blast-injured TBI patients occurred at the Air Force Theater Hospital, 332nd Air Expeditionary Wing, Joint Base Balad, Iraq. Patients were referred from across the combat theater and evaluated as part of routine clinical assessment of psychiatric and neuropsychological symptoms after exposure to an explosive blast. Four measures of neuropsychological functioning were used: the Military Acute Concussion Evaluation (MACE); the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS); the Headminder Cognitive Stability Index (CSI); and the Automated Neuropsychological Assessment Metrics, Version 4.0 (ANAM4). Three measures of combat exposure and psychological functioning were used: the Combat Experiences Scale (CES); the PTSD Checklist-Military Version (PCL-M); and the Acute Stress Disorder Scale (ASDS). Assessments were completed by a deployed clinical psychologist, clinical social worker, or mental health technician. Results: A total of 894 patients were evaluated. Data from 93 patients were removed from the data set for analysis because they experienced a head injury due to an event that was not an explosive blast (n = 84) or they were only assessed for psychiatric symptoms (n = 9). This resulted in a total of 801 blast-exposed patients for data analysis. Because data were collected in-theater for the initial purpose of clinical evaluation, sample size varied widely between measures, from 565 patients who completed the MACE to 154 who completed the CES. Bivariate correlations revealed that the majority of psychological measures were significantly correlated with each other (ps ≤ 0.01), neuropsychological measures were correlated with each other (ps ≤ 0.05), and psychological and neuropsychological measures were also correlated with each other (ps ≤ 0.05). Conclusions: This paper provides one of the first descriptions of psychological and neuropsychological functioning (and their inter-correlation) within days after blast exposure in a large sample of military personnel. Furthermore, this report describes the methodology used to gather data for the acute assessment of TBI, PTSD, and ASD after exposure to an explosive blast in the combat theater. Future analyses will examine the common and unique symptoms of TBI and PTSD, which will be instrumental in developing new assessment approaches and intervention strategies.

Drop-Jump Landing Varies With Baseline Neurocognition: Implications for Anterior Cruciate Ligament Injury Risk and Prevention.

BACKGROUND: Neurocognitive status may be a risk factor for anterior cruciate ligament (ACL) injury. Neurocognitive domains such as visual attention, processing speed/reaction time, and dual-tasking may influence ACL injury risk via alterations to neuromuscular performance during athletic tasks. However, the relationship between neurocognition and performance during athletic tasks is not yet established. HYPOTHESIS: Athletes with low baseline neurocognitive scores will demonstrate poorer jump landing performance compared with athletes with high baseline neurocognitive score. STUDY DESIGN: Controlled laboratory study. METHODS: Neurocognitive performance was measured using the Concussion Resolution Index (CRI). Three-dimensional kinematic and kinetic data of the dominant limb were collected for 37 recreational athletes while performing an unanticipated jump-landing task. Healthy, nonconcussed subjects were screened using a computer-based neurocognitive test into a high performers (HP; n = 20; average CRI percentile, 78th) and a low performers (LP; n = 17; average CRI percentile, 41st) group. The task consisted of a forward jump onto a force plate with an immediate rebound to a second target that was assigned 250 milliseconds before landing on the force plate. Kinematic and kinetic data were obtained during the first jump landing. RESULTS: The LP group demonstrated significantly altered neuromuscular performance during the landing phase while completing the jump-landing task, including significantly increased peak vertical ground-reaction force (mean ± SD of LP vs HP: 1.81 ± 0.53 vs 1.38 ± 0.37 body weight [BW]; P < .01), peak anterior tibial shear force (0.91 ± 0.17 vs 0.72 ± 0.22 BW; P < .01), knee abduction moment (0.47 ± 0.56 vs 0.03 ± 0.64 BW × body height; P = .03), and knee abduction angle (6.1° ± 4.7° vs 1.3° ± 5.6°; P = .03), as well as decreased trunk flexion angle (9.6° ± 9.6° vs 16.4° ± 11.2°; P < .01). CONCLUSION: Healthy athletes with lower baseline neurocognitive performance generate knee kinematic and kinetic patterns that are linked to ACL injury. CLINICAL RELEVANCE: Neurocognitive testing using the CRI may be useful for identification of athletes at elevated risk for future ACL injury.

Utility of a multimodal neurophysiologic assessment tool in distinguishing between individuals with and without a history of mild traumatic brain injury.

This was a preliminary validation study of a multimodal concussion assessment battery incorporating eye-tracking, balance, and neurocognitive tests on a new hardware platform, the Computerized Brain Injury Assessment System. Using receiver-operating characteristics analyses, (1) we identified a subset of the most discriminating neurophysiological assessment tests involving smooth pursuit eye movement tracking errors, corrective saccade counts, a balance score ratio sensitive to vestibular balance performance, and two neurocognitive tests of response speed and memory/incidental learning; (2) we demonstrated the enhancement in discriminatory capability of detecting concussion-related deficits through the combination of the identified subset of assessments; and (3) we demonstrated the effectiveness of a robust and readily implemented global scoring approach was demonstrated for both eye track and balance assessment tests. These results are significant in introducing a comprehensive solution for concussion assessment that incorporates an economical, compact, and mobile hardware system and an assessment battery that is multimodal and time efficient and whose efficacy has been demonstrated on a preliminary basis. This represents a significant step toward the goal of a system capable of making a dependable return-to-play/duty determination based on concussion likelihood.

Sports concussion assessment and management: future research directions.

Over the past 2 decades, major progress has been achieved toward advancing the translational science of sport-related concussion (SRC), paving the way for evidence-based guidelines for injury diagnosis, evaluation and management. Several key empirical questions on the basic and clinical science of SRC, however, remain unanswered. The aim of this summary article is to highlight gaps in the existing science of SRC and to propose a platform for the next generation of SRC research. The article is framed around addressing two key questions that have major significance to protecting the health and safety of athletes affected by SRC, including: (a) Who is at risk of slow recovery or poor outcome after SRC, and why? (b) How does one modify the risks of slow recovery and poor outcome after SRC? Another aim of this article is to stimulate thought among researchers who will carry the science of SRC into the future, including neuropsychology leaders in the field. Implications for the broader science of traumatic brain injury are also discussed.

Return to combat duty after concussive blast injury.

Little data exist regarding the acute assessment of blast concussion and the course of recovery in the combat zone, as most research has examined service members long after they have returned home. This manuscript examined a case series of 377 service members seen for acute concussion evaluation following medical evacuation from the battlefield in Helmand Province, Afghanistan. Of these, 111 were assessed for concussion prior to their return to the continental USA for other severe physical injuries. Of the remainder, and when comparing those who returned to duty (RTD)/recovered from concussion in the combat zone and those who did not, data indicate that those who did not RTD were older and were more likely to endorse symptoms of combat stress. Quicker recovery times were associated with less severe headaches and fewer acute symptoms at the time of injury as well as the absence of combat stress reaction. Variables that were not associated with RTD and/or recovery were Military Acute Concussion Evaluation (MACE) cognitive scores and whether or not individuals suffered loss of consciousness. While MACE scores were not associated with recovery, they were deemed clinically useful as a part of a serial concussion evaluation if the initial MACE was given within 6 h of the blast. Implications for battlefield concussion assessment and management as well as future research directions are discussed.

Mild traumatic brain injury: lessons learned from clinical, sports, and combat concussions.

Over the past forty years, a tremendous amount of information has been gained on the mechanisms and consequences of mild traumatic brain injuries. Using sports as a laboratory to study this phenomenon, a natural recovery curve emerged, along with standards for managing concussions and returning athletes back to play. Although advances have been made in this area, investigation into recovery and return to play continues. With the increase in combat-related traumatic brain injuries in the military setting, lessons learned from sports concussion research are being applied by the Department of Defense to the assessment of blast concussions and return to duty decision making. Concussion management and treatment for military personnel can be complicated by additional combat related stressors not present in the civilian environment. Cognitive behavioral therapy is one of the interventions that has been successful in treating symptoms of postconcussion syndrome. While we are beginning to have an understanding of the impact of multiple concussions and subconcussive blows in the sports world, much is still unknown about the impact of multiple blast injuries.

Differential rates of recovery after acute sport-related concussion: electrophysiologic, symptomatic, and neurocognitive indices.

PURPOSE: To determine if motor evoked potentials (MEPs), postconcussion signs and symptoms, and neurocognitive functions follow a similar recovery pattern after concussion. METHODS: Nine collegiate athletes with acute concussion (>24 hours after injury) participated in this retrospective time series design. Transcranial magnetic stimulation was applied over the motor cortex, and MEPs were recorded from the contralateral upper extremity. Self-reported symptoms were evaluated using the Head Injury Scale, and the Concussion Resolution Index was used to assess neurocognitive function. All measures were repeated on days 3, 5, and 10 after injury. RESULTS: Composite scores on the Head Injury Scale were significantly higher on day 1 after injury (F3,51 = 15.3; P = 0.0001). Processing speed on the Concussion Resolution Index was slower on days 1, 3, and 5 compared with that on day 10 (F3,24 = 6.75; P = 0.0002). Median MEP latencies were significantly longer on day 10 compared with day 1 after concussion (t8 = -2.69; P = 0.03). Ulnar MEP amplitudes were significantly smaller on day 3 after concussion compared with day 5 (t8 = -3.48; P = 0.008). CONCLUSIONS: Acutely concussed collegiate athletes demonstrate changes in MEPs, which persist for up to 10 days after injury and do not follow the same recovery pattern as symptoms and neuropsychological test performance. The apparent differential rates of recovery most likely indicate different pathophysiological processes occurring in the immediate postconcussion period.

Movements during sleep correlate with impaired attention and verbal and memory skills in children with adenotonsillar hypertrophy suspected of having obstructive sleep disordered breathing.

BACKGROUND: Children with obstructive sleep disordered breathing (OSDB) have both impaired cognitive performance and frequent movements during sleep. It is not known whether movements during sleep are related to cognitive function. METHODS: We studied 56 children with adenotonsillar hypertrophy suspected of having OSDB with actigraphy for six consecutive days and nights, followed by cognitive and performance tests. Attended polysomnography was performed on the seventh night. RESULTS: Slower reaction time correlated with both higher sum of all movements during Time in Bed (r(2)=0.19, p=0.001) and higher number of minutes with >5 movements/night (r(2)=0.23, p=0.0003). Low Vocabulary, Similarities and General Memory Index scores correlated with more consolidation of movements (consecutive minutes with >5 movements) (r(2)=0.16, p=0.002, r(2)=0.16, p=0.0026, respectively). Correlation with Vocabulary and Similarities scores improved when Time in Bed was added as an independently significant covariate (r(2)=0.25, p=0.0006, r(2)=0.27, p=0.00028, respectively). Actigraphy correlated with Vocabulary and Similarities scores as well as polysomnography. Other cognitive or behavioral scores were not correlated with actigraphy or polysomnography. Children with more consolidation of movements had higher values for log10(OAHI+1) (r(2)=0.38, p=0.000001). CONCLUSIONS: (1) Frequency of movement during sleep correlated with impaired vigilance while consolidation of movements correlated with impaired verbal and memory skills. (2) OAHI was associated with more consolidation of movements.

The relationship between psychological distress and baseline sports-related concussion testing.

OBJECTIVE: This study examined the effect of psychological distress on neurocognitive performance measured during baseline concussion testing. DESIGN: Archival data were utilized to examine correlations between personality testing and computerized baseline concussion testing. Significantly correlated personality measures were entered into linear regression analyses, predicting baseline concussion testing performance. Suicidal ideation was examined categorically. SETTING: Athletes underwent testing and screening at a university athletic training facility. PARTICIPANTS: Participants included 47 collegiate football players 17 to 19 years old, the majority of whom were in their first year of college. INTERVENTIONS: Participants were administered the Concussion Resolution Index (CRI), an internet-based neurocognitive test designed to monitor and manage both at-risk and concussed athletes. Participants took the Personality Assessment Inventory (PAI), a self-administered inventory designed to measure clinical syndromes, treatment considerations, and interpersonal style. MAIN OUTCOME MEASURES: Scales and subscales from the PAI were utilized to determine the influence psychological distress had on the CRI indices: simple reaction time, complex reaction time, and processing speed. RESULTS: Analyses revealed several significant correlations among aspects of somatic concern, depression, anxiety, substance abuse, and suicidal ideation and CRI performance, each with at least a moderate effect. When entered into a linear regression, the block of combined psychological symptoms accounted for a significant amount of baseline CRI performance, with moderate to large effects (r = 0.23-0.30). When examined categorically, participants with suicidal ideation showed significantly slower simple reaction time and complex reaction time, with a similar trend on processing speed. CONCLUSIONS: Given the possibility of obscured concussion deficits after injury, implications for premature return to play, and the need to target psychological distress outright, these findings heighten the clinical importance of screening for psychological distress during baseline and post-injury concussion evaluations.

A preliminary investigation of motor evoked potential abnormalities following sport-related concussion.

BACKGROUND: Assessment of concussion is primarily based on self-reported symptoms, neurological examination and neuropsychological testing. The neurophysiologic sequelae and the integrity of the corticomotor pathways could be obtained by evaluating motor evoked potentials (MEPs). OBJECTIVES: To compare MEPs obtained through transcranial magnetic stimulation (TMS) in acutely concussed and non-concussed collegiate athletes. METHODS: Eighteen collegiate athletes (12 males, six females, aged 20.4 +/- 1.3 years) including nine subjects with acute concussion ( 0.05). CONCLUSION: MEP abnormalities among acutely concussed collegiate athletes provide direct electrophysiologic evidence for the immediate effects of concussion.

A review of driving simulator parameters relevant to the Operation Enduring Freedom/Operation Iraqi Freedom veteran population.

There is currently a pressing need for safe, reliable, cost-effective methods of evaluating driving ability. With recent improvements in virtual reality technology, driving simulators seem to offer a promising alternative to on-road methods of driving assessment. One population at risk for driving difficulties may be veterans returning from combat in Iraq or Afghanistan. The use of driving simulators to evaluate and remediate veterans' abilities to operate a motor vehicle is a rehabilitative goal. However, there are no consistent standardized procedures for determining safe from unsafe driving using driving simulators, which limit the clinical utility of this important tool. The purposes of this article are (1) to give the reader a better understanding of the parameters that are most commonly measured in the driving simulation literature and (2) to review parameters that are most relevant for the Operation Enduring Freedom/Operation Iraqi Freedom veteran population.

Secretive recording of neuropsychological testing and interviewing: official position of the National Academy of Neuropsychology.

Neuropsychologists are occasionally asked to have neuropsychological testing observed via the presence of a third party, through one-way mirrors, or with audio or video monitoring or recording devices. The primary reasons for not allowing observation are its effect on the validity of the examination results and the security of copyrighted test materials. To overcome the problem of observer effects on the examinee's performance, some individuals have suggested that examinations be monitored or recorded without the examinee's awareness (i.e., secretly). However, secretive recording of neuropsychological interviews and testing is deceptive, which is inconsistent with ethical principles. In addition, such recording may affect the behavior of the examiner. For these reasons, neuropsychologists do not, and should not, encourage, condone, or engage in secret recording of neuropsychological interviews or testing.

Recommendations for diagnosing a mild traumatic brain injury: a National Academy of Neuropsychology education paper.

A special interest group of the American Congress of Rehabilitation Medicine [ACRM; Mild Traumatic Brain Injury Committee. (1993). Definition of mild traumatic brain injury. Journal of Head Trauma Rehabilitation, 8 (3), 86-87.] was the first organized interdisciplinary group to advocate four specific criteria for the diagnosis of a mild traumatic brain injury (TBI). More recently, the World Health Organization (WHO) Collaborative Center Task Force on Mild Traumatic Brain Injury [Carroll, L. J., Cassidy, J. D., Holm, L., Kraus, J., & Coronado, V. G. (2004). Methodological issues and research recommendations for mild traumatic brain injury: the WHO Collaborating Centre Task Force on Mild Traumatic Brain Injury. Journal of Rehabilitation Medicine, (Suppl. 43), 113-125.] conducted a comprehensive review of the definitions utilized in evidence-based studies with mild TBI patients. Based on this review, the WHO task force maintained the same four criteria but offered two modifications. The similarities and differences between these two definitions are discussed. The authors of the ACRM and the WHO definitions do not provide guidelines or specific recommendations for diagnosing the four criteria. Thus, we provide recommendations for assessing loss of consciousness, retrograde and post-traumatic amnesia, disorientation and confusion as well as clarification of the neurologic signs that can be indicative of a diagnosis of mild TBI. Finally, confounding factors mentioned in both definitions that should exclude a mild TBI diagnosis are summarized.

Neuropsychological consequences of boxing and recommendations to improve safety: a National Academy of Neuropsychology education paper.

Boxing has held appeal for many athletes and audiences for centuries, and injuries have been part of boxing since its inception. Although permanent and irreversible neurologic dysfunction does not occur in the majority of participants, an association has been reported between the number of bouts fought and the development of neurologic, psychiatric, or histopathological signs and symptoms of encephalopathy in boxers. The purpose of this paper is to (i) provide clinical neuropsychologists, other health-care professionals, and the general public with information about the potential neuropsychological consequences of boxing, and (ii) provide recommendations to improve safety standards for those who participate in the sport.

SLAM on the stand: how the sports-related concussion literature can inform the expert witness.

Mild head injury is a controversial topic because patients may have subtle deficits and widely varied outcomes. Accordingly, neuropsychologists are frequently asked to provide expert testimony about the nature of mild head injury. This article discusses how the sports-related concussion literature, including the concept of baseline assessment, can inform expert witnesses who are asked to provide such testimony. We first provide a review of several of the controversies surrounding mild head injury, both within and outside of the forensic context. This is followed by a review of the sports as a laboratory assessment model literature, which demonstrates consistent and meaningful evidence of cognitive sequelae following mild head injury. We conclude with a description of how the sports as a laboratory assessment model literature may be utilized in a forensic neuropsychology context to address some of the identified controversies. We end with a call for more research that will further inform the forensic neuropsychologist about mild head injury and those factors that may result in poor recovery.

The prediction of change: normative neuropsychological trajectories.

While the application of normative standards is vital to the practice of clinical neuropsychology, data regarding normative change remains scarce despite the frequency of serial assessments. Based on 285 normal individuals, we provide co-normed baseline data with demographic adjustments and test-retest standardized regression based (SRB) models for three time points for several measures. These models delineate normal, expected change across time, and yield standardized z-scores that are comparable across tests. Using a new approach, performance on any previous trial was accounted for in the subsequent models of change, yielding serial normative formulas that model change trajectories rather than simple change from point to point. These equations provide indices of deviation from expected baseline and change for use in clinical or research settings.

Traumatic brain injury research priorities: the Conemaugh International Brain Injury Symposium.

In 2005, an international symposium was convened with over 100 neuroscientists from 13 countries and major research centers to review current research in traumatic brain injury (TBI) and develop a consensus document on research issues and priorities. Four levels of TBI research were the focus of the discussion: basic science, acute care, post-acute neurorehabilitation, and improving quality of life (QOL). Each working group or committee was charged with reviewing current research, discussion and prioritizing future research directions, identifying critical issues that impede research in brain injury, and establishing a research agenda that will drive research over the next five years, leading to significantly improved outcomes and QOL for individuals suffering brain injuries. This symposium was organized at the request of the Congressional Brain Injury Task Force, to follow up on the National Institutes of Health Consensus Conference on TBI as mandated by the TBI ACT of 1996. The goal was to review what progress had been made since the National Institutes of Health (NIH) Consensus Conference, and also to follow up on the 1990's Decade of the Brain Project. The major purpose of the symposium was to provide recommendations to the U.S. Congress on a priority basis for research, treatment, and training in TBI over the next five years.

Long-term outcomes and prognostic factors in pediatric patients with severe traumatic brain injury and elevated intracranial pressure.

OBJECT: The management strategies and outcomes in pediatric patients with elevated intracranial pressure (ICP) following severe traumatic brain injury (TBI) are examined in this study. METHODS: This study was a retrospective review of a prospectively acquired pediatric trauma database. More than 750 pediatric patients with brain injury were seen over a 10-year period. Records were retrospectively reviewed to determine interventions for correcting ICP, and surviving patients were contacted prospectively to determine functional status and quality of life. Only patients with 2 years of follow-up were included in the study. RESULTS: Ninety-six pediatric patients (age range 3-18 years) were identified with a Glasgow Coma Scale score<8 and elevated ICP>20 mm Hg on presentation. The mean injury severity score was 65 (range 30-100). All patients were treated using a standardized head injury protocol. The mean time course until peak ICP was 69 hours postinjury (range 2-196 hours). Intracranial pressure control was achieved in 82 patients (85%). Methods employed to achieve ICP control included maximal medical therapy (sedation, hyperosmolar therapy, and paralysis) in 34 patients (35%), ventriculostomy in 23 patients (24%), and surgery in 39 patients (41%). Fourteen patients (15%) had refractory ICP despite all interventions, and all of these patients died. Seventy-two patients (75%) were discharged from the hospital, whereas 24 (25%) died during hospitalization. Univariate and multivariate analysis revealed that the presence of vascular injury, refractory ICP, and cisternal effacement at presentation had the highest correlation with subsequent death (p<0.05). Mean follow-up was 53 months (range 11-126 months). Three patients died during the follow-up period (2 due to infections and 1 committed suicide). The mean 2-year Glasgow Outcome Scale score was 4 (median 4, range 1-5). The mean patient competency rating at follow-up was 4.13 out of 5 (median 4.5, range 1-4.8). Univariate analysis revealed that the extent of intracranial and systemic injuries had the highest correlation with long-term quality of life (p<0.05). CONCLUSIONS: Controlling elevated ICP is an important factor in patient survival following severe pediatric TBI. The modality used for ICP control appears to be less important. Long-term follow-up is essential to determine neurocognitive sequelae associated with TBI.